Technical data

Checking Block Consistency and Time Stamps as a Block Property
15.3 Time Stamps in Logic Blocks
Programming with STEP 7
328 Manual, 05/2010, A5E02789666-01
15.3 Time Stamps in Logic Blocks
Code Time stamp
The time and date the block was created is entered here. The time stamp is updated:
• When the program code is changed
• When the interface description is changed
• When the comment is changed
• When an ASCII source file is created for the first time and compiled
• When the block properties ("Properties" dialog box) are changed
Interface Time stamp
The time stamp is updated:
• When the interface description is changed (changes to data types or initial values, new
parameters)
• When an ASCII source file is created for the first time and compiled, if the interface is changed
structurally.
• The time stamp is not updated:
• When symbols are changed
• When comments in the variable declaration are changed
• When changes are made in the TEMP area
Rules for Block Calls
• The interface time stamp of the called block must be older than the code time stamp of the
calling block.
• Only change the interface of a block if no block is open which calls this block. Otherwise, if you
save the calling blocks later than the changed block, you will not recognize this inconsistency
from the time stamp.
Procedure if a Time stamp Conflict Occurs
A time stamp conflict is displayed when the calling block is opened. After making changes to an FC
or FB interface, all calls to this block in calling blocks are shown in expanded form.
If the interface of a block is changed, all blocks which call this block must be adjusted as well.
After making changes to an FB interface, the existing multiple instance definitions and instance
data blocks must be updated.